For the administration of liquid medications to patients, the use of needles is widespread and commonplace. Indeed the use of needles can be traced back to the 17th century when Christopher Wren performed experiments using goose quills as crude hypodermic needles to deliver intravenous injections to dogs in 1656.
Dr. Alexander Wood developed an all glass syringe in 1851, thus permitting the user to estimate dosage based on observing the amount of liquid through the glass as the liquid was injected by a needle into a patient. This development by Dr. Woods significantly advanced the acceptance of injection as a medical technique.
Advancements in metallurgy permitted the manufacturing of needles of consistently specific sizes and bores and aided in 1920's growth acceptance of injecting insulin as treatment for diabetes. Disposable needles and injection systems were further developed in both World War II and the Korean War, but in the main needles themselves have remained largely unchanged.
And so too have the issues of needle care and protection. More specifically, as the needle is intended to breach the skin of a person or subject, the tip of the needle is very sharp. As the needle is often inserted below the dermis layer of the skin, the shaft of the needle can be long—ranging from a few millimeters to perhaps several inches. The shaft of the needle is also typically quite stiff so as not to bend or deflect as it is passed into the tissue of the patient. And as the needle is a foreign object being disposed into the tissues of the patient, it is very important that the needle be clean and sterile so as not to introduce foreign matter or pathogens into the patient.
Moreover, two fundamental tenants apply to needles prior to use—the needle must be protected so as to not inadvertently harm a person handling the needle, an occurrence called a needle stick, and the needle must be kept clean and sterile.
In general there are two types of needle protectors, those that fit loosely over the needle and have a coupling mechanism to engage the base of the needle and those that fit tightly over the needle itself. Forming a coupling mechanism, such as a snap connector often requires additional tooling and fabrication efforts for the both the needle base and the needle protector. In addition, if jarred loose such as by jostling during shipment or handling the protector will fall entirely off thus exposing the needle.
In many instances, such as large scale operations providing needles and needle based infusion sets for infusion therapy, the use of tight fitting straight protectors is common. These needle protectors are typically provided by an extrusion process and are intended to have nearly the same internal diameter as the outside diameter of the needle upon which they are to be used. As such, these tight fitting needle protectors remain in place due to friction between the needle and the needle protector.
Because these needle protectors are typically manufactured by an extrusion process, issues with that process, i.e. the rate of extrusion, can easily result in needle protectors that are too tight or too loose. If the needle protectors are they are too loose, some or all will fall off and thus expose the needle.
If the needle protectors are too tight, during their installation process the needle may shave off bits of the protector and become partially clogged, and thus have a diminished flow rate. This shaving or scraping of the needle protector may also occur with properly sized needle protectors if they are not installed properly.
If shaving occurs and is discovered, this may require some or all of a production run of needles to be scrapped or redone—an issue of both cost and expense to the provider, and potential delay to the end user. Even if the problem is detected, there is always the possibility that a new batch of needle protectors could suffer from the same production issue and be too tight.
In addition, due to the tight fit between the needle protector and the needle some end users who suffer from reduced dexterity and/or hand strength may have significant difficulty at times in removing the needle protector so as to use the needle.
Hence there is a need for a needle protector that overcomes one or more of the above identified challenges.